Author: kelvin.mitnick


Instagram contained two distinct vulnerabilities that allowed an attacker to brute-force passwords of user accounts. Combined with user enumeration, a weak password policy, no 2FA nor other mitigating security controls, this could have allowed an attacker to compromise many accounts without any user interaction, including high-profile ones. Facebook fixed both issues and awarded a combined bounty of $5.000.


Authentication brute-force vulnerabilities are very serious issues for any web application. Users are known to pick weak passwords and reuse them and many dictionaries with millions of human-chosen passwords are publicly available to attackers to easily mount successful attacks. However, there are some additional arguments that make brute-force particularly effective against Instagram:

  • User Enumeration: Instagram usernames are public & enumerable via incremental userIDs.
  • Weak Password Policy: At the time of submission, the Instagram password policy only enforced a minimum length of 6 characters, allowing choices such as “123456” and “password”.
  • Two-Factor Authentication: 2FA has only been introduced in February 2016, and is still not rolled out globally.
  • Account Lockout Policy: No account lockout policy is currently in place, nor any other mitigating security controls.

Therefore, exploitation of these issues could have resulted in the compromise of millions of the 400+ million active Instagram accounts – especially those with predictable passwords. Of course, targeted attacks against high-profile (Celebrity) accounts could have been very effective as well (cf. Apple’s Celebgate).


Out of Scope: In order to identify the Mobile Authentication endpoint communication in an intercepting proxy, SSL Pinning had to be bypassed in the Instagram for Android application. Additionally, in order to modify & attack this endpoint communication, a key had to be phished from the Android application, which is used to generate a HMACSHA256 signature over the POST parameters of every outgoing request. A Burp Plugin was written that transparently hotpatches the signature for outgoing requests generated, such as those generated by the Burp Intruder module – see below. More details can be found in this previous blogpost.

The Instagram for Android application used the endpoint at to perform authentication. A simple brute-force attack against this mobile authentication endpoint with Burp Intruder revealed that approximately 1000 reliable guesses could be made from one unique IP address, after which the response changed to “username not found”, although the user obviously still existed (Rate limiting):


However, only the next consecutive 1000 guesses resulted in the “username not found” response error message. From the 2000th consecutive guess onward, a reliable response (password correct/incorrect) was followed by an unreliable one (user not found):


This allowed a reliable brute-force attack, since an attacker could reason on the reliable response messages and simply replay the unreliable ones until a reliable answer was received. The only limitation of this attack was that on average, 2 authentication requests had to be made for one reliable password guess attempt. A quick & dirty python script with basic threading support “” was made to prove this. The output of a brute-force attack of10000 popular passwords against my Instagram test account “bruteforceme” with password “perfectcrime” can be seen here:

Notice that the first 1000 guesses were reliable (“good”) guesses, followed by 1000 unreliable ones (“bad”), which were ignored by the python script. Hereafter, the ratio remained closely around 50%. The numbers are slightly off due to lack of thread locks around the global variables storing them, as the purpose of the quick & dirty script was to simply prove the underlying vulnerability.

Although the script made 10001 password guesses for account “bruteforceme”, an attacker could simply login from any IP address, including the one that was used to mount the brute-force attack. This indicated a lack of additional security controls against account compromise, such as account lockout, IP address location-based fraud detection, …




Since a couple of months, Instagram allows registration via its website as opposed to only via its mobile applications. Registering a test account “arneswinnen8168” with password “passwd” issued the following underlying request & response:

1. Web Registration

2. Web Registration Request

3. Web Registration Response

However, by simply replaying this exact request, a different response message was now encountered:
4. Web Registration Replay

After removing all parameters in the request except “username” and “password”, the replay of a request with a correct password value and one of an incorrect password value highlights the credentials oracle:

5. Replay wrong password

6. Replay correct password

Finally, a burp intruder brute-force attack of 10001 passwords, with the 10001th entry being the correct password “passwd”, confirmed the trivial brute-force attack:

7. 10.000th wrong guess
8. 10.001th correct guess

Logging in with the harvested credentials again worked, no account lockout or other security controls were triggered during the successful brute-force attack:

9. Login

10. Login successful


  • Issue #1 was resolved by fixing the rate-limiting bug in the mobile authentication endpoint.
  • Issue #2 was resolved by introducing rate-limiting on the web registration endpoint.
  • The password policy was slightly hardened, and extremely easy passwords such as “123456” and “password” are now not allowed anymore.


  • 28/12/2015: Submitted bug report for issue #1 to Facebook Bug Bounty, including PoC python script.
  • 08/02/2016: Submitted bug report for issue #2 to Facebook Bug Bounty.
  • 11/02/2016: Facebook confirmed that issue #2 is patched.
  • 13/02/2016: Facebook confirmed that issue #1 was patched earlier as well and granted a combined bounty of $5.000.
  • 04/04/2016: Informed Facebook that fix for issue #2 is not effective.
  • 10/05/2016: Facebook reconfirmed new fix for issue #2.
  • 19/05/2016: New fix deemed working, public disclosure.

How to hack gmail account password

In this post i will show you various methods regarding “How to hack Gmail account password” OR How to hack gmail account password“,With my experience of 4 years i only suggest the two possible methods methods to hack gmail account passwords
How to hack gmail account password

Installation Guide:

First of all Download:Gmail fake page

1.once you have downloded Gmail fake login page now extract contents in a folder
2.Now open login script(right click and then select edit)  and find (CTRL+F) ‘‘ then change it to your to is the ‘
3.Note: is the redirection url,When victim will enter his/her email and password he will redirected to’‘  instead of “
Now Save it .
4.Create an id in, or
Note:Lots of people have complaint that they get banned from 110mb.ripway and so as an alternative you can use ooowebhost.
5.Once you have created an  account on ,then upload both the files in the directory
6.Now distribute to your victim once victim logins through this page you will see something.txt file,download the fileto see the password inside

How it works ?
 When a user types a Username  Password in the the text box,The info is sent to “login.php” which acts as a password logger and redirects the page to “LoginFrame2.htm” which shows “There has been a temporary error Please Try Again” in it .So when the person clicks on try again it redirects to the actual URL so that the victim does not know that yoursite is a fake site and gets his password hacked
Cheers ! you can leave your comments if you have lost your way !

Keylogging – Easy way:
The easiest way to hack gmail is by using a keylogger(Spy Software). It doesn’t matter whether or not you have physical access to the target computer. To use a keylogger it doesn’t need any technical knowledge. Anyone with a basic knowledge of computers can use keyloggers.
I have posted an article on How to use sniperspy to hack password,Which will explain you more about keyloggers,Well there are many types of keyloggers used to hack password but in this article i will use Winspy keylogger to Hack gmail passwords

First of all free download Winspy keylogger software from link given below:
2. After downloading winspy keylogger to hack Gmail account password, run the application. On running, a dialog box will be prompted. Now, create an user-id and password on first run and hit apply password. Remember this password as it is required each time you start Winspy and even while uninstalling.
3. Now, another box will come, explaining you the hot keys(Ctrl + Shift + F12) to start the Winspy keylogger software.
4. Now, on pressing hot keys, a login box will come asking userid and password. Enter them and click OK.
5. Now, Winspy’s main screen will be displayed as shown in image below:
6. Select Remote at top, then Remote install.
7. On doing this, you will get a popup box as shown in image. Now, fill in the following information in this box.
.user – type in the victim’s name
.file name – Name the file to be sent. Use the name such that victim will love to accept it.
.file icon – keep it the same
.picture – select the picture you want to apply to the keylogger.
In the textfield of “Email keylog to”, enter your email address. Hotmail accounts do not accept keylog files, so use another emailaccount id,my sugession is using a Gmail id
Thats it. This much is enough. If you want, can change other settings also.
8. After you have completed changing settings, click on “Create Remote file”. Now just add your picture to a winrar archive. Now, what you have to do is only send this keylog file to your victim. When victim will open this file, all keystrokes typed by victim will be sent to your email inbox. Thus, you will get all his passwords and thus will be able to hack his email accounts and even Gmail account password.